UNIVERSITY  OF  CALIFORNIA  PUBLICATIONS 

COLLEGE  OF  AGRICULTURE 

AGRICULTURAL  EXPERIMENT  STATION 

BERKELEY,  CALIFORNIA 


THE  SEEDLESS  RAISIN  GRAPES 


BY 
FREDERIC   T.    BIOLETTI 


BULLETIN  No.  298 

(September,  1918) 
Revised  May,  1921 


UNIVERSITY   OF  CALIFORNIA  PRESS 
BERKELEY,  CALIFORNIA 


David  P.  Barrows,  President  of  the  University. 

EXPERIMENT  STATION  STAFF 

HEADS  OF  DIVISIONS 

Thomas  Forsyth  Hunt,  Dean. 

Edward  J.  Wickson,  Horticulture  (Emeritus). 

Walter  Mulford,  Forestry,  Director  of  Resident  Instruction. 

C.  M.  Haring,  Veterinary  Science,  Director  of  Agricultural  Experiment  Station. 

B.  H.  Crocheron,  Director  of  Agricultural  Extension. 
Hubert  E.  Van  Norman,  Vice-Director;  Dairy  Management. 

James  T.  Barrett,  Acting  Director  of  Citrus  Experiment  Station ;  Plant  Pathology. 
William  A.  Setchell,  Botany. 
Myer  E.  Jaffa,  Nutrition. 
Ralph  E.  Smith,  Plant  Pathology. 
John  W.  Gilmore,  Agronomy. 
Charles  F.  Shaw,  Soil  Technology. 

John  W.  Gregg,  Landscape  Gardening  and  Floriculture. 
Frederic  T.  Bioletti,  Viticulture  and  Fruit  Products. 
Warren  T.  Clarke,  Agricultural  Extension. 
John  S.  Burd,  Agricultural  Chemistry. 
Charles  B.  Lipman,  Soil  Chemistry  and  Bacteriology. 
Ernest  B.  Babcock,  Genetics. 
Gordon  H.  True,  Animal  Husbandry. 
Fritz  W.  Woll,  Animal  Nutrition. 
W.  P.  Kelley,  Agricultural  Chemistry. 
H.  J.  Quayle,  Entomology. 
Elwood  Mead,  Rural  Institutions. 
H.  S.  Reed,  Plant  Physiology. 
L.  D.  Batchelor,  Orchard  Management. 
J.  C.  Whitten,  Pomology. 
fFRANK  Adams,  Irrigation  Investigations. 

C.  L.  Eoadhouse,  Dairy  Industry. 

F.  L.  Griffin,  Agricultural  Education. 
John  E.  Dougherty,  Poultry  Husbandry. 
W.  B.  Herms,  Entomology  and  Parasitology. 
L.  J.  Fletcher,  Agricultural  Engineering. 
Edwin  C.  Voorhies,  Assistant  to  the  Dean. 

division  of  viticulture  and  fruit  products 
Frederic  T.  Bioletti  W.  V.  Cruess 

L.  O.  Bonnett  A.  W.  Christie 

G.  Barovetto 


t  In  cooperation  with  Office  of  Public  Roads  and  Rural  Engineering,  TJ.  S.  Department  of 
Agriculture. 


THE  SEEDLESS   RAISIN  GRAPES 

By  FREDERIC  T.  BIOLETTI 


INTRODUCTION 

Types  of  Baisins. — The  raisins  of  the  world  are  of  four  main 
types:  (1)  of  large  size,  made  principally  from  the  Muscat  of  Alex- 
andria grape  and  known  generally  as  Muscat  or  Malaga  raisins;  (2) 
of  medium  size,  light  colored  and  seedless,  made  principally  from  the 
Sultanina  grape  and  known  generally  as  Sultana  raisins;  (3)  of  small 
size,  dark  colored  and  seedless,  made  principally  from  the  Black 
Corinth  grape  and  known  in  English  as  Currants;  (4)  of  various  sizes, 
colors,  and  qualities,  and  made  from  almost  any  vinifera  varieties,  and 
usually  known  as  Dried  Grapes.  The  last  are  not  generally  classified 
as  raisins.  There  are  numerous  subdivisions  and  modifications  of  these 
types.    This  bulletin  deals  with  the  second  and  the  third  types. 

Statistics. — The  principal  raisin-producing  countries  of  the  world 
are  Greece,  California,  Turkey,  Spain,  and  Australia.  Their  com- 
parative importance  is  shown  by  the  following  figures:1 

World's  Production  of  Baisins  in  1913 

Per  cent 
Principal  types  Country  Tons  of  total 

Muscats  and  Sultanas  California  65,000  22 

Currants  Greece  180,000  60 

Sultanas  Turkey 23,000  8 

Muscats  Spain  20,000  7 

Muscats  and  Currants  Australia 14,000  5 

The  California  crop  increased  from  40,000  to  128,000  tons  (220 
per  cent)  between  1904  and  1915.  During  the  same  period,  the  crop 
of  Australia  increased  136  per  cent,  while  that  of  Spain  decreased 
26  per  cent.  Those  of  Turkey  and  Greece  were  practically  stationary. 
In  1916,  California  produced  about  one  half  the  raisins  of  the  world. 

Kinds  of  Baisins  in  California. — The  raisin  crop  of  California  in 
1916  was  as  follows : 

Muscats  89,000  tons  =  67.4% 

f  Thompson's  23,500  tons 

*Sultanas  \  Sultanas,  seedless  7,000  tons 

[Bleached 7,000  tons 

37,500  tonsrr:  28.4% 

Dried  Grapes  5,500  tons  =     4.2% 

Total 132,000  tons  =100.0% 

*These  include  the  dried  Sultanina  (Thompson)  and  Sultana  grapes. 

i  All  statistics  are  quoted  or  calculated  from  those  given  by  George  Robertson 
in  the  Statistical  Report  of  the  California  State  Board  of  Agriculture  for  1916. 


4  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION 

Comparison  of  Muscat  and  Seedless  Eaisin  Crops  in  California 

Muscats  Sultanas 

I \  I \ 

Year  Tons  Per  cent  Tons  Per  cent 

1913  49,294  76.3  15,322  23.7 

1914  60,000  69.0  27,000  31.0 

1915  78,123  82.0  17,260  18.0 

1916  89,000  70.4  37,500  29.6 

Mean  ratio,  74.4  Mean  ratio,  25.6 

There  is  no  confirmation  here  of  the  commonly  expressed  opinion 
that  the  crop  of  seedless  raisins  has  been  increasing  much  more  rapidly 
than  that  of  the  Muscat  raisins.  Approximately  one  quarter  of  the 
total  crop  is  of  Sultana  type  and  three  quarters  of  Muscat  type. 
Probably  the  influence  of  the  large  plantings  of  Sultanina  which  have 
undoubtedly  been  made  during  recent  years  will  be  evident  in  future 
crops. 

VARIETIES 

Most  of  the  seedless  raisins  of  commerce  are  made  from  two 
varieties — the  Sultanina  and  the  Black  Corinth.  The  Sultana  and  the 
White  Corinth  make  raisins  of  similar  type,  but  are  much  less  exten- 
sively grown.  The  Black  Monukka  is  said  to  be  the  favorite  raisin 
grape  of  Persia  and  is  beginning  to  be  dried  in  California.  The  Rose 
Sultanina  is  used  principally  as  a  table  grape.  Seedless  raisins  of  a 
type  peculiar  to  California  are  also  made  from  the  abortive  seedless 
berries  ("shot  grapes")  which  occur  commonly  on  the  Muscat  of 
Alexandria  and  which  are  separated  in  the  cleaning  and  grading  of 
Muscat  raisins. 

The  various  seedless  grapes  and  their  uses  are  shown  in  the  follow- 
ing table : 

Seedless  Grapes  and  Their  Uses 

Name  of  grape:  Use: 

Sultanina  Sultanas  of  commerce 

Sultanina,  Eose  Table  grape 

Sultanina,  Giant  Curiosity  of  collections 

Sultana  Inferior  Sultanas  of  commerce 

Black  Corinth  Currants 

White  Corinth  Inferior  currants 

Black  Monukka  Table  grape  and  raisins 

Muscat  ("shot  grapes")  Seedless  muscats 

Sultanina. — Synonyms:  Thompson,  Thompson's  Seedless  (in  Cali- 
fornia), Lady  de  Coverly  (English  hothouses),  Sultanieh,  Oval-fruited 
Kishmish   (Turkey,  Palestine).     This  variety  is  grown  in  collections 


Bulletin  298  TIIE  SEEDLESS  RAISIN  GRAPES  5 

or  in  small  quantities  as  a  table  grape  throughout  the  Mediterranean 
region.  It  is  grown  largely  in  the  Levants,  more  particularly  in  the 
warmer  parts  of  Asia  Minor,  as  a  raisin  grape.  It  appears  to  be  widely 
distributed  in  Asia  as  far  east  as  Persia  and  probably  beyond.  From 
it  are  made  the  genuine  Sultana  raisins  of  Smyrna. 

It  was  brought  to  California  in  1872  by  Wm.  Thompon,  Sr.,  of 
Sutter  County,  who  obtained  it  from  Ellwanger  and  Barry,  of 
Rochester,  New  York,  under  the  name  of  Lady  de  Coverley,  a  name 
by  which  it  is  known  in  English  hothouses.  It  was  distributed  here 
under  the  name  of  Thompson's  Seedless  to  distinguish  it  from  the 
Seedless  Sultana,  a  grape  grown  more  sparingly  in  the  same  Asiatic 
regions.  Its  name  of  Sultanina,  by  which  it  is  known  in  most  countries, 
or  Sultanieh,  as  it  is  sometimes  spelled,  a  name  derived  from  the  town 
of  Soultanieh,  in  Persia. 

Mr.  Thompson  deserves  great  credit  for  having  introduced  this 
valuable  grape  into  California,  but  it  seems  hardly  necessary  or  desir- 
able to  change  the  euphonious  and  appropriate  name  by  which  it  has 
been  known  in  most  of  the  regions  where  it  has  been  grown  probably 
for  hundreds  of  years. 

The  vine  is  remarkably  vigorous,  producing  in  rich  soil  canes  often 
thirty  feet  long.  These  canes  are  often  comparatively  thin  and  slightly 
flattened  for  a  foot  or  so  near  the  trunk  and  become  rounded  and 
much  thicker  in  their  middle  portion.  The  joints  are  very  long,  and 
strong  laterals  are  produced  abundantly,  especially  when  the  growing 
shoots  are  pinched  or  topped. 

The  bunches  are  very  large,  conical,  and  usually  well  filled.  The 
berries  are  oval,  yellow,  and  small  to  under  medium  in  size.  They 
are  perfectly  seedless,  without  marked  flavor,  and  low  in  acidity. 

Rose  Sultanina. — Synonym:  Sultanina  Rosea.  This  is  a  mere  color 
variation  of  the  last,  with  which  it  is  identical  in  all  respects  but  the 
color  of  the  fruit.  It  was  imported  from  Italy  by  the  United  States 
Department  of  Agriculture  in  1900.  It  is  numbered  5616  (3921)  in 
the  list  of  plant  introductions  published  by  the  Department.  It  is 
known  in  European  vine  collections  and  appears  to  have  been  brought 
to  Europe  from  some  part  of  Anatolia  (Asia  Minor). 

Raisins  have  been  made  from  it,  but  they  are  inferior  in  color  to 
those  made  from  the  ordinary  or  white  Sultanina.  As  a  table  grape, 
it  is  very  attractive  when  it  attains  its  full,  bright  rose  color.  In  the 
hotter  regions  of  the  state,  as  Imperial,  Fresno,  and  Yolo  counties, 
it  remains  white  or  only  faintly  pink  and  is  less  attractive  in  appear- 
ance than  the  ordinary  form.     It  develops  a  most  brilliant  color  in 


6  UNIVERSITY   OP    CALIFORNIA — EXPERIMENT   STATION 

Sonoma  County  and  probably  would  do  so  in  any  of  the  cooler  grape- 
growing  regions. 

Giant  Sultanina. — Occasionally,  a  vine  of  Sultanina  is  found  show- 
ing a  remarkable  hypertrophy  of  all  its  parts.  The  berries  are  round 
and  nearly  as  large  as  those  of  Muscat.  The  peduncles,  canes,  joints, 
pith,  and  leaves  also  show  this  enlargement.  Vines  obtained  by  graft- 
ing or  rooting  cuttings  from  this  form  retain  its  peculiarities. 

The  vine  is  evidently  a  bud  sport  showing  the  characteristics  of 
what  the  biologists  call  "gigantism."  Mr.  L.  F.  Arnold,  near  Merced, 
found  a  branch  of  this  form  growing  on  the  trunk  of  an  ordinary 
Sultanina.  This  proves  its  nature  of  a  bud  sport  and  indicates  that 
the  specimens  found  in  various  parts  of  California  may  have  had 
several  independent  origins.  If  this  is  the  case  a  careful  search  among 
the  various  forms  might  result  in  the  discovery  of  a  type  free  from 
the  defects  noted  below.  If  this  could  be  done,  the  large  size  of  the 
berry  would  be  of  great  value. 

It  is  possible  that  this  vine  has  given  rise  to  the  legend  of  a  seedless 
Muscat.  It  has,  however,  none  of  the  flavor  or  other  characteristics 
of  the  Muscat  and,  in  fact,  in  spite  of  its  marked  peculiarities,  no  one 
familiar  with  varieties  of  vines  would  fail  to  recognize  it  as  a  form  of 
the  Sultanina.  It  is  now  growing  at  the  experiment  vineyard  at 
Davis,  but  the  crops  so  far  have  been  small  and  irregular.  It  appears 
to  lack  vigor  and  is  somewhat  difficult  to  propagate. 

Similar  cases  of  gigantism  have  been  noted  with  Muscat  of  Alex- 
andria, Flame  Tokay,  and  Zinfandel.  It  seems  probable  that  it  is  a 
variation  similar  to  that  of  the  Nectarine  and  that  it  may  occur  with 
any  variety.  All  the  varieties  in  which  it  has  been  noted  are  grown 
in  large  quantities,  which  increases  the  chance  of  finding  a  very  rare 
variation. 

Sultana. — Synonyms:  Seedless  Sultana  (in  California),  round- 
berried  Kishmish  (French  ampelographies).  This  grape  was  intro- 
duced very  early  into  California  by  Mr.  West,  a  Stockton  nurseryman. 
Under  the  mistaken  impression  that  it  was  the  variety  from  which 
the  Sultana  raisins  of  commerce  were  made,  it  was  distributed  under 
this  name.  This  is  unfortunate,  as  the  name  became  fixed  in  popular 
use  here  before  the  Sultanina,  the  real  variety  producing  Sultana 
raisins,  was  introduced. 

The  grape  seems  to  have  been  introduced  into  Europe  from  Asiatic 
Turkey.  In  Turkish,  any  seedless  grape  or  raisin  is  called  Kishmish 
and  two  varieties  are  recognized,  the  "round-fruited,"  which  we  call 
the  Sultana,  and  the  ' '  oval-fruited, ' '  which  is  the  true  Sultanina,  and 
which  we  call  the  Thompson. 


Bulletin  298  TnE  SEEDLESS  RAISIN  GRAPES  7 

The  vine  resembles  the  Sultanina  in  its  vigor  and  general  aspect. 
It  is  a  little  less  riotous  in  its  growth  and  a  little  more  inclined  to  be 
fruitful,  even  with  defective  pruning. 

The  bunches  are  very  large,  compact,  and  of  a  very  characteristic 
shape.  The  central  part  is  remarkably  long  and  perfectly  cylindrical, 
and  the  upper  part  very  heavily  shouldered.  The  berries  are  wider 
than  they  are  long  and  slightly  flattened  at  the  apex.  In  flavor  and 
color,  they  resemble  the  Sultanina,  but  are  inclined  to  have  a  higher 
acidity.    A  seed  is  found  in  an  occasional  berry. 

Black  Corinth. — Synonyms:  Zante  Currant,  Panariti(  ?),  Passerina 
nera  (in  Italy).  This  variety  was  early  introduced  into  California 
and  planted  in  various  places  in  the  Sacramento  and  San  Joaquin 
valleys.  Later  introductions  by  the  United  States  Department  of 
Agriculture  were  widely  distributed.  Unlike  the  Sultanina,  it  was 
never  largely  planted  as  no  one  until  lately  has  been  able  to  make 
it  produce  paying  crops.  By  severe  annual  ringings  of  the  main 
trunk,  it  has  been  made  to  produce  satisfactorily  in  Australia,  and 
fair  crops  have  been  obtained  in  the  University  experiment  vineyards 
by  grafting  it  on  resistant  stocks. 

The  vine  is  of  great  vigor  and  the  trunk  will  grow  a  hundred  or 
more  feet  in  length  if  given  the  opportunity.  Under  some  conditions, 
apparently  when  it  is  allowed  to  grow  to  very  large  size,  many  or  most 
of  its  berries  grow  large  and  develop  seeds.  In  such  cases,  it  is  of  no 
value  as  a  raisin  grape.  It  is  from  this  variety  that  the  so-called 
Zante  or  Greek  currants  are  made. 

The  bunches  are  of  medium  size,  compact  and  cylindrical,  with 
well-marked  shoulders  and  sometimes  winged.  The  berries  are  very 
small,  no  larger  than  elderberries,  reddish  black,  round,  and  seedless. 
Occasionally  a  berry  containing  seeds  is  found. 

White  Corinth. — Synonym:  Passerina  bianca  (in  Italy).  This 
variety  resembles  the  last  one  in  many  of  its  characteristics.  It  is, 
however,  more  easily  made  to  bear  good  crops,  and  several  small  vine- 
yards of  this  variety  have  been  in  existence  in  the  Sacramento  Valley 
for  many  years.  It  will  boar  on  its  own  roots  and  with  the  same  treat- 
ment that  succeeds  with  the  Sultanina. 

The  vine  is  nearly  as  vigorous  as  the  Black  Corinth,  the  leaves  are 
a  little  lighter  in  color,  and  the  fruit  is  white.  The  bunches  are 
medium  or  a  little  larger  than  those  of  the  Black  and  more  conical  in 
shape.  The  berries  are  a  little  larger,  intermediate  in  size  between  the 
Black  Corinth  and  the  Sultana.  They  are  rounded  and  slightly  flat- 
tened like  the  latter  variety.  They  lack  the  flavor  and  acidity  of  the 
black.      "When  dried,  they  make  an  excellent  currant,  but  not  equal 


O  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

to  those  from  the  Black.  The  dried  fruit  is  intermediate  between  a 
currant  and  a  Sultana  and,  though  intrinsically  of  good  quality,  it 
must  be  marketed  as  a  second-grade  currant  or  Sultana. 

Red  Corinth. — Synonym:  Passerina  rosa  (in  Italy).  This  variety 
does  not  seem  to  have  been  introduced  into  California.  Some  vines 
called  by  this  name  are  simply  Black  Corinth  that,  owing  to 
peculiarities  of  local  soil  or  climate,  do  not  develop  their  full  color. 

Black  Monukka. — This  is  the  most  promising  grape  which  has  been 
introduced  into  California  for  many  years.  It  has  been  marketed 
successfully  as  a  table,  a  shipping,  and  a  raisin  grape. 

The  vine  is  even  more  vigorous  than  the  Sultanina.  It  develops 
quickly  and  comes  into  bearing  early,  and  bears  well  with  short  or 
long  pruning.  When  cane-pruned  it  has  a  tendency  to  overbear.  It 
is  probably  best  suited  to  cordon  pruning  with  spurs. 

The  bunches  are  large,  conical,  shouldered  and  well-filled.  The 
berries  are  larger  than  those  of  the  Sultanina  and  ripen  several  days 
earlier.  They  are  elongated,  purplish  black  with  firm  pulp  and  pleas- 
ing though  neutral  flavor.  They  are  practically  seedless  for,  while 
abortive  seeds  occur  in  most  of  the  berries,  these  are  soft  and  not 
noticeable  in  eating.  The  raisins  are  of  excellent  appearance,  texture, 
and  flavor.  They  constitute  a  type  of  raisin  entirely  new  to  commerce, 
but  judging  by  the  reception  they  have  met  by  the  few  consumers  to 
whom  they  have  been  offered  they  should  bave  no  difficulty  in  finding 
a  market. 

The  Monukka  was  sent  to  the  United  States  Department  of  Agri- 
culture by  the  Reverend  W.  Wilts,  of  the  Royal  Horticultural  Society 
of  London.  According  to  A.  F.  Barron,  it  came  to  England  from 
India.    It  is  probably  the  Munaqqa,  a  Persion  raisin  grape. 

Seedless  Muscat. — There  have  been  rumors  for  many  years  that  a 
large  seedless  Muscat  is  grown  in  Chile,  but  no  one  has  been  able  to 
obtain  any  for  California.  It  is  not  likely  that  such  a  variety  exists. 
A  seedless  grape  is  a  defective  grape,  that  is,  one  which  bas  not 
developed  the  physiologically  essential  part  of  the  fruit,  the  seed, 
and  this  defect  seems  to  be  correlated  with  small  size.  The  seedless 
Muscats  are  grapes  which  have  been  imperfectly  pollenized  and  in 
some  seasons  they  occur  in  large  numbers  on  most  of  the  bunches,  but 
it  is  rare  that  they  constitute  all  the  berries  of  a  bunch.  This  con- 
dition is  called  by  French  grape  growers  "millerandage"  and  by 
California  grape  growers  "shot  grapes."  It  occurs  sometimes  with 
nearly  all  varieties. 


Bulletin  298  THE  SEEDLESS  RAISIN  GRAPES  9 

LOCATION    AND    SOIL 

Location. — The  present  location  of  the  vineyards  of  seedless  raisin 
grapes  is  indicated  by  the  returns  of  raisins  in  1916  from  tin;  various 
counties : 

Distribution  op  Crop  of  Suitana  Raisins*  in  1916 

Per  cent  of  total  crop 

Fresno  County  73.2 

Tulare  County  10.8 

Kings  County  1.7 

Merced  County .4 

Madera  County  .3 

Kern  County J 

Stanislaus  County  .1 

San  Joaquin  Valley  86.6 

Sutter  County 10.5 

Yolo  County  2.7 

Sacramento  Valley  13.2 

Southern  California  .2 


100.00 


Nearly  nine  tenths  of  the  seedless  raisins  of  California  are  pro- 
duced in  the  upper  San  Joaquin  Valley,  where  the  soil  and  climate 
are  particularly  suitable.  The  vines  grow  and  bear  as  well  in  several 
other  districts,  but  the  conditions  for  raisin  making  are  not  quite  so 
favorable.  In  the  San  Joaquin  Valley,  62  per  cent  of  the  seedless 
grapes  are  Sultanina,  in  the  Sacramento  Valley,  84  per  cent.  In 
Yolo  County,  on  the  west  side  of  the  Sacramento  River,  only  20  per 
cent  are  Sultanina  and  the  rest  Sultana,  while  in  Sutter  County  on 
the  east  side,  the  proportion  of  Sultanina  is  over  99  per  cent.  These 
differences  are  probably  not  due  to  any  differences  of  adaptation  of 
the  two  varieties  to  the  various  localities,  but  rather  to  accidental 
historical  causes  related  to  the  first  plantings.  Both  varieties  sei  m 
to  do  equally  well  in  all  these  localities  when  given  proper  treatment. 

In  southern  California,  the  Sultana  is  grown  almost  exclusively 
as  a  seedless  raisin  grape.  The  Sultanina  has  not  given  such  good 
results,  perhaps  owing  to  a  lack  of  knowledge  of  how  to  prune  it. 

In  all  the  counties  where  seedless  raisins  are  produced,  and  in  other 
counties,  some  Sultanina  grapes  are  shipped  and  marketed  fresh  as 


*  Where  the  expression  "Sultana  raisins"  occurs  without  qualification,  it 
includes  all  of  what  are  commonly  known  in  California  as  "Thompson  and 
Seedless  Sultanas." 


10  UNIVERSITY   OP    CALIFORNIA — EXPERIMENT   STATION 

table  grapes.  Imperial  County  in  particular  ships  a  large  quantity 
very  early  in  the  season. 

None  of  the  other  seedless  grapes  are  grown  in  California  in  large 
commercial  quantities.  There  have  been  a  few  small  vineyards  of 
White  Corinth  in  Placer  County  for  some  years.  The  Black  Corinth 
has  been  planted  in  several  localities  during  the  last  few  years,  but 
usually  not  in  large  quantities.  The  Black  Monukka  is  attracting 
much  attention  and  for  the  last  two  seasons  all  cuttings  that  could  be 
procured  have  been  planted.  The  total  present  area  covered  by  all 
three,  however,  is  probably  below  1000  acres. 

Any  of  the  seedless  grapes  will  grow  and  ripen  their  fruit  in 
almost  any  of  the  grape-growing  districts  of  California,  but  they  bear 
better  in  the  warmer  parts.  For  raisin  making,  they  must  be  grown 
in  districts  where  they  ripen  early,  before  the  usual  arrival  of  autumn 
rains.  This  has  so  far  confined  raisin  production  to  the  interior 
valleys  and  southern  California.  The  early  ripening  of  the  Black 
Corinth  and  of  the  Black  Monukka  may  make  it  possible  to  extend 
the  area  of  raisin  production.  The  same  effect  may  be  expected  from 
improvements  in  the  construction  of  dehydrators. 

As  a  shipping  table  grape,  only  the  Sultanina  is  grown  extensively. 
Some  more  or  less  successful  shipments  of  fresh  Black  Corinth  have 
been  made  to  eastern  points  where  their  peculiar  appearance  and 
small  size  have  proved  attractive.  They  are  said  to  have  been  marketed 
as  "California  Huckelberries'  and  used  for  pies.  The  few  eastern 
shipments  which  have  been  made  of  fresh  Black  Monukka  have  suc- 
ceeded so  well  that  there  seems  a  strong  probability  that  this  variety 
may  be  a  successful  rival  of  the  Sultanina  as  an  early  table  grape. 

Soils. — Owing  to  their  great  vigor,  the  Sultanina  and  Sultana  will 
give  paying  crops  on  light  sandy  soils  where  most  other  varieties  fail. 
They  will  give  larger  crops,  however,  on  better  soils  and  it  is  unsafe 
to  plant  them  where  the  crops  are  likely  to  be  less  than  the  average. 
While  prices  are  high,  such  crops  may  be  profitable,  but  when  prices 
fall  they  cannot  compete  with  heavier  crops  from  better  soil. 

The  adaptation  of  the  Corinth  grapes  is  not  well  known.  It  is 
probably  similar  to  that  of  the  Sultanina.  The  Black  Monukka  has 
grown  vigorously  and  borne  well  in  practically  all  cases  where  it  has 
been  tried.  It  has  succeeded  under  extremes  of  climate  ranging  from 
that  of  Contra  Costa  County  to  that  of  Imperial  and  in  soils  ranging 
from  heavy  black  adobe  to  sandy  loam. 


Bulletin  298  THE  seedless  raisin  GRAPES  11 

PLANTING    THE    VINEYARD 

Preparation  of  the  Ground. — The  best  results  can  be  obtained  with 
vines  only  if  the  ground  is  properly  prepared  before  planting.  It 
should  be  cleared  of  stumps  and  rocks,  properly  graded,  especially 
where  irrigation  is  to  be  practiced,  and  plowed  as  deep  as  is  prac- 
ticable, at  least  ten  inches.  Any  troublesome  weeds,  such  as  Morning 
Glory,  Johnson  grass,  or  Bermuda  grass  should  be  eradicated  before 
planting.  Hardpan  within  three  feet  should  be  blasted  at  every  point 
where  a  vine  is  to  be  planted.  A  few  years  as  an  alfalfa  field  is  an 
excellent  preparation.  In  irrigated  districts,  a  crop  of  cow-peas  or 
similar  leguminous  crop  grown  in  the  summer  and  plowed  in  deep 
during  the  autumn  prepares  the  soil  perfectly  for  planting  during 
the  following  spring. 

Planting  Stock. — For  planting,  cuttings,  rooted  vines,  or  bench- 
grafts  may  be  used. 

Cuttings  are  almost  as  good  as  rooted  vines  if  they  can  be  made 
to  grow  during  the  first  year.  The  Sultanina,  however,  is  rather  hard 
to  root  and  many  usually  fail  during  the  first  year.  The  result  is 
that  much  replanting  is  necessary,  the  vines  are  uneven  in  size,  the 
vineyard  is  slower  coming  to  full  bearing,  and  the  cost  in  the  end  may 
be  as  large  or  larger  than  when  rooted  vines  are  used.  The  best 
cuttings  are  those  of  medium  size  with  fairly  close  joints.  "Well-grown 
laterals  of  the  Sultanina  often  make  the  best  cuttings.  The  other 
varieties  root  more  easily,  especially  the  Black  Monukka.  In  most 
cases,  it  is  best  to  use  one-year-old  rooted  vines  of  moderate  size.  If 
of  good  quality  and  properly  handled,  practically  every  one  will  grow 
the  first  year  and  a  full  crop  may  be  obtained  the  third  or  fourth 
season  following  planting. 

In  districts  infested  with  phylloxera,  bench-grafts  on  resistant 
stocks  should  be  used.  These  are  more  expensive,  but  are  the  only 
known  defense  against  the  pest.  The  extra  cost  is  in  part  counter- 
balanced by  the  fact  that  the  vines  on  resistant  stocks  bear  earlier  and 
perhaps  better  than  on  their  own  roots.  Many  varieties  of  resistant 
stocks  have  been  tested  at  Kearney  and  Davis.  All  have  given  good 
to  very  good  results  with  the  Sultanina  and  Sultana.  The  Corinths 
seem  to  be  more  difficult  to  please  and  the  other  varieties  have  not 
been  very  thoroughly  tested. 

The  Sultanina  has  done  best  at  Davis  on  A.  X  R.  No.  1  and  101-14. 
On  these  stocks  it  has  borne  more  than  when  ungrafted.  On  all  other 
stocks  it  has  borne  less,  especially  on  St.  George,  where  it  has  yielded 
only  one  half.    At  Kearney  the  best  crops  have  been  obtained  on  1202, 


12  UNIVERSITY    OP    CALIFORNIA — EXPERIMENT   STATION 

3306,  and  3309,  but  all  stocks  have  done  well,  though  St.  George  is 
near  the  bottom  of  the  list. 

The  Sultana  has  given  the  best  crops  on  41-B,  420-A,  and  A.  X  R- 
No.  1  and  1202.  St.  George  has  a  fair  record  with  this  variety  at 
Kearney  but  a  poor  record  at  Davis. 

The  Black  Corinth  has  yielded  most  on  41-B,  Riparia  gloire,  and 
3306.  It  has  done  poorly  on  St.  George  and  has  failed  entirely  on 
420-A.     The  White  Corinth  has  given  the  best  results  on  3306. 

Laying  out  the  Vineyard. — In  laying  out  the  vineyard,  two  points 
have  to  be  determined:  (1)  the  area  to  be  given  to  each  vine,  and 
(2)  the  arrangement  of  the  vines. 

As  all  seedless  vines  are  vigorous  growers,  they  require  abundant 
room.  If  crowded,  they  may  give  a  little  more  in  the  first  one  or  two 
crops,  but  the  yield  will  be  less  later  and  the  cost  of  handling  greater. 
The  appropriate  space  for  each  vine  will  vary  from  about  seventy 
square  feet  to  about  a  hundred  and  thirty,  according  to  the  variety 
and  the  soil.  The  Sultana  may  be  planted  a  little  closer  than  the 
others  without  injury.  In  rich,  deep  soil  where  the  vines  will  be 
exceptionally  vigorous,  they  must  be  given  more  room;  in  sandy, 
shallow,  or  poor  soil,  they  should  be  placed  closer. 

As  all  these  varieties  require  long  pruning  and  trellising,  the 
vineyard  should  be  laid  out  on  the  avenue  system.  The  following 
table  gives  the  arrangements  and  distances  which  are  recommended: 

Arrangement  and  Distances  for  Seedless  Vines 

Rich  Soil  Poor  Soil* 

< * 1  , • 1 

Distances,            Area,  Vines,  Distances  Area,           Vines, 

Variety                                     feet       square  feet  per  acre  feet  square  feet  per  acre 

Sultana  14x6             84  518  12x6  72           605 

Sultanina   14x7             98  444  12x6  72           605 

Corinth  14x7             98  444  12x6  72           605 

Black  Monukka 16x8           128  340  14x6  84           518 

Intermediate  distances  may  be  adopted  for  intermediate  cases. 
The  distance  apart  of  the  vines  in  the  row  should  in  no  case  be  less 
than  six  feet,  as  this  is  the  minimum  that  will  give  room  for  the 
necessary  three  and  four-foot  fruit  canes.  The  rows  should  in  no 
case  be  nearer  than  twelve  feet,  as  this  is  the  minimum  that  will 
allow  of  inexpensive  and  efficient  cultivation.  It  is  better  to  err  on 
the  side  of  wide  planting  than  of  narrow,  for  there  is  no  practical 
limit  to  the  size  these  vines  can  be  made  to  grow  except  the  difficulty 
of  supporting  them;  a  large  vine  will  bear  at  least  as  much  as  two 
vines  of  half  the  size  and  will  be  less  costly  to  prune  and  cultivate. 

*  The  word  "poor"  is  used  relatively.  An  infertile  soil  should  not  be  used 
for  vines  of  any  kind. 


Bulletin  298  T]IE  SEEDLESS  RAISIN  GRAPES  13 

COST    AND    RETURNS* 

It  may  be  estimated  roughly  that  the  expenses  of  a  vineyard  of 
seedless  raisin  grapes,  Sultanina,  Sultana,  or  Corinth,  properly 
managed  will  amount,  on  the  average,  to  about  $95  per  acre.  This 
includes  vineyard  work,  drying  and  delivering  the  crop,  water,  taxes, 
depreciation,  and  6  per  cent  interest  on  an  investment  of  $350  per 
acre,  and  is  based  on  a  crop  of  V/2  tons  of  raisins,  which  is  about  the 
average.  This  indicates  that  a  price  of  3  cents  per  pound  will  just 
cover  the  expenses  of  the  average  vineyard  and  allow  6  per  eenl 
interest  on  a  moderate  valuation  of  the  property.  It  allows  nothing 
for  superintendence. 

A  price  of  5  cents  per  pound  for  the  raisins  would  yield  a  profit 
of  $55  per  acre  and  a  crop  of  three  tons  a  profit  of  $60.  If  both  price 
and  crop  were  increased  in  these  proportions,  the  profit  would  be  $180 
per  acre.      These  calculations  are  based  on  the  following  estimates : 

Estimated  Cost  op  a  Vineyard  of  Seedless  Grape  Vines 
(Good  level  land,  irrigation^  resistant  vines,  trellis) 

Land  $200.00 

Bench  grafts  (500)  30.00 

Preparation  of  land 15.00 

Planting 10.00 

Cultivating  5.00 

Interest  and  taxes 15.00 

Cost  the  first  year $275.00 

Pruning  $3.00 

Staking 10.00 

Replanting   5.00 

Cultivation  5.00 

Hand  work  10.00 

Interest  and  taxes 22.00 

Cost  the  second  year  55.00 

Pruning  $5.00 

Cultivation   5.00 

Hand  work  10.00 

Trellising 55.00 

Interest  and  taxes  25.00 

Gross  cost,  third  year  $100.00 

Crop,  one  ton  at  4  cents  net 80.00 

Net  cost,  third  year  20.00 

Total  cost  $350.00 


*  These  estimates  were  made  in  1918.  They  can  be  modified  for  changes  in 
cost  of  labor  and  material. 

t  The  cost  of  irrigation  is  not  included,  as  it  varies  too  widely.  It  will  range 
from  $2.50  to  $15.00  per  acre  per  year. 


14  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION 

Estimated  Cost-of  Sultanina  Vineyard 
(Valuation  of  $350) 
Annual  cost  of  maintenance: 

Pruning  and  tying $12.50 

Plowing  and  cultivating  7.50 

Hand  work  10.00 


Vineyard  work  $30.00 

Interest  and  taxes $28.00 

Depreciation  10.00 


Cost 
$85.50 

Net 

returns 
$14.50 

94.25 

55.75 

103.00 

97.00 

111.75 

138.25 

120.50 

179.50 

Fixed  charges  38.00 

Total  $68.00 

Harvesting,  drying,  and  hauling  raisins,  per  ton 17.50 

Profit  per  Acre  at  Five  Cents  per  Pound 

Crop,  Gross 

pounds  returns 

2,000  $100.00 

3,000  150.00 

4,000  200.00 

5,000  250.00 

6,000  300.00 

Although  these  estimates  are  based  on  actual  accounts  and  returns 
from  vineyards,  they  must  be  considered  as  simply  indicating  the 
probabilities.  The  investment,  the  cost  of  maintenance,  the  cost  of 
drying,  the  amount  and  price  of  the  crop,  will  all  vary  within  wide 
limits.  Those  given  must  be  considered  only  as  average  figures  and 
they  refer  more  particularly  to  the  Fresno  region. 

As  iy2  tons  per  acre  is  the  average  crop  of  Sultanina  vineyards  in 
California,  this  indicates  that  at  5  cents  per  pound  for  the  raisins  the 
vineyards  are  fairly  profitable.  Many  vineyards  produce  less  than  a 
ton  and  cannot  be  considered  profitable.  Others  produce  two  tons 
and  are  very  profitable. 

Sultana  vineyards  are,  on  the  whole,  a  little  more  productive,  but 
the  price  of  the  raisins  is  somewhat  lower. 

There  is  little  accurate  information  on  the  yield  of  the  Corinth 
grapes  in  commercial  vineyards.  The  White  Corinth  yields  fairly 
well  on  its  own  roots,  but  the  Black  yields  very  little  unless  subjected 
to  the  operation  of  girdling  or  ringing.  This  consists  of  removing  a 
narrow  ring  of  bark  from  the  trunk  near  the  surface  of  the  ground. 
This  must  be  done  every  year  about  the  time  of  blossoming,  preferably 
a  little  after.  On  suitable  resistant  stocks  the  Black  Corinth  gives 
good  crops  at  first  without  girdling,  but  later  requires  the  operation  as 
much  as  when  growing  on  its  own  roots. 

An  idea  of  the  possibilities  of  crop  in  good  soil  and  with  proper 
care  is  given  by  the  following  records  of  the  experimental  vineyards 
at  Kearney  and  Davis. 


Bulletin  298 


THE   SEEDLESS   RAISIN    GKAPES 


15 


Yields  op  Seedless 

;  Vines  at 

the  Experiment  Vineyards 

(In  pounds  of  raisins  per 

acre) 

Number 

Age 

Variety 

Locality 

of  vines 

of  vines 

Year 

Crop 

Sultanina 

Davis 

192 

5 

1915 

2,500 

Sultanina 

Davis 

144 

6 

1916 

5,5 1'6 

Sultanina 

Davis 

240 

7 

1917 

2,632 

Sultanina,  grafted 

Kearney 

32 

3 

1914 

4,172 

Sultanina,  grafted 

Kearney 

98 

3-4 

1915 

5,252 

Sultanina,  grafted 

Kearney 

82 

4-5 

1916 

8,366 

Sultanina,  grafted 

Kearney 

83 

5-6 

1917 

6,414 

Sultana 

Davis 

38 

3 

1914 

3,239 

Sultana 

Davis 

38 

4 

1915 

3,800 

Sultana 

Davis 

38 

5 

1916 

5,486 

Sultana 

Davis 

38 

6 

1917 

6,840 

Sultana,  grafted 

Davis 

75 

5 

1917 

4,838 

Sultana,  grafted 

Kearney 

56 

4 

1915 

8,026 

Sultana,  grafted 

Kearney 

82 

5 

1916 

8,792 

Sultana,  grafted 

Kearney 

67 

6 

1917 

7,563 

Black  Corinth 

Davis 

38 

5 

1914 

723 

Black  Corinth 

Davis 

38 

6 

1915 

0 

Black  Corinth 

Davis 

38 

7 

1916 

167 

Black  Corinth 

Davis 

38 

8 

1917 

158 

Black  Corinth,  grafted 

Davis 

48 

5 

1915 

308 

Black  Corinth,  grafted 

Davis 

48 

6 

1916 

1,153 

Black  Corinth,  grafted 

Davis 

48 

7 

1917 

1,608 

Black  Corinth,  grafted 

Kearney 

9 

5 

1916 

3,178 

Black  Corinth,  grafted 

Kearney 

9 

6 

1917 

2,301 

White  Corinth 

Davis 

38 

5 

1914 

1,245 

White  Corinth 

Davis 

38 

6 

1915 

827 

White  Corinth 

Davis 

38 

7 

1916 

2,727 

White  Corinth 

Davis 

38 

8 

1917 

1,733 

White  Corinth,  grafted 

Davis 

24 

5 

1915 

192 

White  Corinth,  grafted 

Davis 

24 

6 

1916 

2,968 

White  Corinth,  grafted 

Davis 

24 

7 

1917 

1,251 

White  Corinth,  grafted 

Kearney 

14 

5 

1916 

4,539 

White  Corinth,  grafted 

Kearney 

17 

6 

1917 

1,817 

Average  Annual  Crop  op  Seedless  Raisins 

Number  of 

Pounds 

years 

i 

per  acre 

Sultanina,  ungrafted 

Davis 

3 

3,549 

Sultanina,  grafted 

Kearney 

4 

6,051 

Sultana,  ungrafted 

Davis 

4 

4,839 

Sultana  grafted 

Davis 

1 

4,838 

Sultana,  grafted 

Kearney 

3 

8,127 

Black  Corinth,  ungrafted 

Davis 

4 

262 

Black  Corinth,  grafted 

Davis 

3 

1,023 

Black  Corinth,  grafted 

Kearney 

2 

2,740 

White  Corinth,  ungrafted 

Davis 

4 

1,633 

White  Corinth,  grafted 

Davis 

3 

1.471 

White  Corinth,  grafted 

Kearney 

2 

3,178 

